Mercerization



- UNH STATS PATENT @FFHCE.

SAMUEL MANSFIELD JONES AND IVAN OTHMA HARLOW, OF NORTH ADAMS, MASSA- CHUSETTS, ASSIGNORS T0 ARNOLD PRINT WORKS, OF NORTH ADAMS, MASSACHU- SETTS, A CORPORATION OIE MASSACHUSETTS.

MERCERIZATION.

Ito Drawing. Application filed June 21,

To aZZ whom it may concern:

Be it known that we, SAMUEL MANSFIELD JONES and IVAN OTHMA HARLOW, both,'respectively, citizens of the United States, and residents of North Adams, in the county of Berkshire and State of Massachusetts, have jointly invented new and useful Improvements in Mercerization, of which the following is a description.

In the process of mercerizing cellulosic fibers of natural growth, such as cotton and linen, when these are interwoven or otherwise intermingled with filaments of artificial silk known as viscose, certain methods of protecting such viscose filaments from dele terious attack by the caustic alkali employed for mercerization have been already set forth and claimed in United States patents to Samuel Mansfield Jones numbered and dated respectively, 1,316,958, September 23, 1910; 1,343,133 and 1,343,139, June 3, 1920; 1,346,302 and 1,340,803, July 13, 1020.

The methods thus patented for protecting the viscoss have consistedin the modification of the mercerizing caustic alkali solution by the addition thereto of either monohydric alcohol or formic aldehyde or phenol or glycerin or monacetin, each of which is an oxy-hydro-carbon compound belonging to that division of chemistry commonly designated as organic; but we have discovered that the modification of the mercerizing caustic alkali solution by the addition thereto of'certain salts having inorganic bases may be made to accomplish similar useful results; and our present invention consists essentially in employing for this purpose such a salt of an inorganic base as when introduced into an aqueous solution of caustic alkali suitable for mercerizing cellulosic fibers, will not by reaction of the caustic alkali therewith undergo change of chemical composition but will be soluble in the caustic alkali solution of standard strength for ordinary merceri zation to an amount not much less and preferably more than twenty per centum of this solvent. The salt of this constitution and capacity is to be dissolved to the full extent of its solubility in the mercerizing caustic alkali solution which it is thus employed to modify.

The salts of most of the metals, even including the salts of magnesium and of the metals of the alkaline earths, when intro- Specification of Letters Patent.

vention.

Patented Oct. 4, 192 1.

1921. Serial No. 479,414.

cerization will respectively, by reaction of.

the caustic alkali therewith, be converted into hydroxids of their metal bases or undergo further transformation into other salts, neither of which, either because of its change of chemical composition or because of its practical insolubility, is capableof modifying such caustic alkali solution so as to accomplish the intended object of this in- Our investigations have shown, however, that'all the salts of sodium, potassium and ammonium, whether formed with inorganic acids or with organic acids embraced in the aliphatic category, or in other words the salts of what may be termed inorganic alkali bases, are more or less soluble in the standard mercerizing caustic alkali solution, and, when dissolved in this solution to the full extent of their respective solubilities therein, tend in greater or lesser degrees to modify it in the direction of protecting the Viscose silk intermixed with the cellulosic fibers to be mercerized against the injurious attack of the caustic alkali; but that the injury resulting from such attack is only partially counteracted and is too considerable for economic requirements if the solubility of these modifying salts is in any case much below twenty per centum of the weight of the solvent constituted by the standard mercerizing caustic alkali solution; and that in order to obtain an entirely satisfactory protection of the viscose silk under the conditions indicated this percentage should be exceeded.

Among the salts which are soluble to the extent thus specified as practically available for the purposes of the present 1nvention the following may be mentioned as typical, to wit: sodium nitrite, sodium formate, sodium citrate, sodium lactate, potassium sulfite, potassium formate, potassium acetate, potassium citrate and ammonlum c1- trate; but the best of these has proved to be potassium acetate which when introduced into the standard caustic alkali solution for ordinary mercerization, is' capable of bemg dissolved therein to an extent amounting to .fective for mercerizing the cellulosic fibers ofa fabric into which viscose silk filaments have been incorporated and at the same time affords complete protection to such viscose silk against impairment of either its tensile strength of its luster.

Except for the modification of the mercerizing caustic alkali solution suitable for ordinary mercerization by the addition thereto of any salt of an inorganic alkali base which is soluble in such solution to an amount not much less than twenty per centum of the weight of that solvent and which is dissolved therein to the full extent of its solubility, the treatment of the fabric into which cellulosic fibers of natural growth have been interwoven with viscose silk is in other respects substantially the same as that customarily employed in the mercerization of woven fabrics composed entirely of cotton, including the usual means and mode of applying tension thereto for the prevention of shrinkage.

Manifestly also by employing the same modified mercerizing solution as in the treatment of woven mixed fabrics of the kind just specified, this invention may like wise be practised upon yarns or other unwoven fabrics which are composed partly of mercerizable cellulosic fibers, such as cotton or linen, and partly of viscose silk filaments and which in addition to their subjection to the action of such modified mercerizing solution are to be otherwise treated in the same manner as in the process of ordinary mercerization applied to similar yarns or unwoven fabrics consisting entirely of mercerizable cellulosic fibers.

By way of further explanation it may be more explicity stated that the caustic alkali solution of standard strength for ordinary mercerization of natural cellulosic fibers usually consists of an aqueous solution of sodium hydroxid; that twenty-seven per centum of the total weight of this solution is sodium hydroxid; that such solution has a density indicated by 60 of Twaddells hydrometer; and that the extent of solubility of the respective soluble salts of the inorganic bases hereinabove referred to is estimated and intended to be specified in percentage of the weight of the said standard mercerizing solution without regard to the specific gravity of any solution resulting from the introduction of either of those salts into such standard solution.

Finally, it may here be particularly remarked that although the arsenites and arseniates of sodium, potassium and ammonium if employed to modify the mercer-.

izing caustic alkali solution are sufliciently soluble and effective therein to protect the viscose silk from practical deterloration in its tensile strength and degree of luster when intermingled with cellulosic fibers which are subjected to the process of mer mercerizing cerization; yet because of the well-known poisonous properties of arsenical COIIl-r pounds, precautions should be taken to wash out any residue of the alkali arsenite 'or arseniate left in the composite textile fabric after treatment as aforesaid in order to render such fabric hygienioally acceptable for thereto of a salt which has an inorganic base and which will not by reaction of the caustic alkali therewith undergo change in its chemical composition, but which is soluble in the standard aqueous caustic alkali solution for ordinary mercerization to an amount not much less than twenty per 'centum of the weight of such solvent, and is in fact dissolved to substantially the full extent of its solubility in the mercerizing caustic alkali solution employed in said process.

2. The method of treating textile fabrics composed of yarn spun from mercerizable cellulosic fibers and interwoven with artificial silk filament of viscose for the purpose of mercerizing the fibers of such yarn without practical injury to the viscose silk, by subjecting the woven fabric thus constituted to a process of mercerization wherein the solution of caustic alkali is modified by the addition thereto of a salt which has an inorganic base and which will not by reaction of the caustic alkali therewith undergo change in its chemical composition, but which is soluble in the standard aqueous caustic alkali solution for ordinary mercerization to an amount not much less than twenty per centum'of the weight of such solvent, and is in fact dissolved to substantially the full extent of its solubility in the mercerizing caustic alkali solution employed in said process.

3. The method of treating textile fabrics composed of mercerizable cellulosic fibers intermixed with artificial silk filaments of fact dissolved to substantially the full extent of its solubility in the mercerizing caustic alkali solution employed in said process,

4. The method of treating textile fabrics composed of yarn spun from mercerizable cellulosic fibers and interwoven with artificial silk filaments of viscose for the purpose of mercerizing the fibers of such yarn without practical injury to' the viscose silk, by subjecting the woven fabric thus constituted to a process of mercerization wherein mercerizing caustic alkali solution employed in said process.

5. The method of treating textile fabrics composed of cotton fibers intermixed with artificial silk filaments of viscose for the purpose of mercerizing such cotton fibers without practical injury to the viscose silk, by subjecting the composite fabric thus constituted to a process of mercerization wherein the mercerizing solution of caustic alkali is modified by the addition thereto of a salt which has an inorganic alkali base and which is soluble in the standard aqueous caustic alkali solution for ordinary mercerization to an amount not much less than twenty per centum of the weight of such solvent, and is in fact dissolved to substantially the full extent of its solubility in the mercerizing caustic alkali solution employed in said process.

6. The method of treating textile fabrics composed of cotton yarn interwoven with artificial silk filaments of viscose for the purpose of mercerizing the fibers of such cotton yarn without practical injury to the viscose .silk by subjecting the woven fabric thus constituted to a process of mercerization wherein the mercerizing solution of caustic alkali is modified by the addition thereto of a salt which has an inorganic alkali base and which is soluble in the stand 'ard aqueous caustic alkali solution for ordinary mercerization to an amount not much less than twenty per centum of the weight of such solvent and is in fact dissolved'to substantially the full extentof its solubility in the mercerizing caustic alkali solution employedin said process.

7. The method of treating textile fabrics composed of mercerizable cellulosic fibers intermixed with artificial silk filaments'of viscose for the purpose of mercerizing such cellulosic fibers without injury to the viscose silk by subjecting the composite fabric thus constituted to a process of mercerization wherein the mercerizing solution of caustic alkali is modified by the addition thereto of potassium acetate dissolved therein to substantially the full extent of its solubility.

8. The method of treating textile fabrics composed of yarn spun from mercerizable cellulosic fibers and interwoven with artificial silk filaments of viscose for the purpose of mercerizing the fibers of such yarn without injury to the viscose silk, by sub- ;jecting the woven fabric thus constituted to a process of mercerization wherein the mercerizing solution of caustic alkali is modified by the addition thereto of potassium acetate dissolved therein tosubstantially the full extent of its solubility.

9. The method of treating textile fabrics composed of cotton fibers intermixed'with artifical silk filaments of viscose for the purpose of mercerizing such cotton fibers without injury to the viscose silk by subj ecting the composite fabric thus constituted to a process of mercerization wherein the mercerizing solution of caustic alkali is modified by the addition thereto of otassium acetate dissolved therein to su stantially the full extent of its solubility.

10. The method of treating textile fabrics composed of cotton yarn interwoven with artifical silk filaments of viscose for the purpose of mercerizing the fibers of such cotton yarn without injury to the viscose silk, by subjecting the woven fabric thus constituted to a process of mercerization wherein the mercerizing solution of caustic alkali is modified by the addition thereto of potassium acetate dissolved therein to substantially the full extent of its solubility.

SAMUEL MANS FIEDD JONES. IVAN OTHMA HARLOW. 

